UMASS/AMHERST 


31EDt.hDDSaSSDfl7 


mill;- 


it!!:.'"  ■     ■ 


Pi     . 


f!l  pp  !!i  ifiiiiijili;: 

iii'P        vr: 

will'"'  ''^.''    !<)'•' 

mm" 
[.'.'liiiiiiiiii  ■■•. 


lis 


> 


^vi:„.,,iJiSiii 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 

Boston  Library  Consortium  IVIember  Libraries 


http://www.archive.org/details/positionoflimeinOOwarn 


M    '    ' 


The  Position  of  Lime 


m 


the  Chemistry  of   the  Soil 


published    by 
Charles    Warner    Company 


m^mm 


The  Position  of  Lime 

in 

the  Chemistry  of  the  Soil 


A  paper  read  before 
The  National  L^ime  Manufacturers'  Association 

February,   1910 


By 
IRVING  WARNER 


Published  by 
CHARLES  WARNER  COMPANY 

Wilmington  Philadelphia  New  York  Boston 


The    Position    of  Lime 

in 

the  Chemistry  of  the  Soil 


By  Irving  Warner 

THERE  seems  to  be  such  general  misunderstanding  as  to 
the  actual  needs  of  agricultural  soils  that  it  is  timely  that 
a  resume  or  summary  be  given,  the  object  of  which  is  to 
bring  about  a  clearer  comprehension  of  the  fundamentals 
of  the  subject,  not  only  by  the  farmer,  but  also  by  those  who 
cater  to  his  needs, — the  producers  of  limes  and  fertilizers.  It  is  to 
be  regretted  that  there  has  existed  and  still  exists  between  the 
latter  two,  an  antagonism  that  is  entirely  uncalled  for  and  that 
is  not  necessary,  in  order  that  each  may  do  profitable  business 
with  the  farmer  to  his  advantage.  The  actual  facts  of  the  case 
are  that  the  lime  and  the  fertilizers  complement  each  other  and  are 
not  in  competition,  and  the  sooner  this  situation  is  accepted  by 
both  parties,  the  sooner  will  the  confidence  of  the  farmer  replace 
his  present  dovibt  and  misunderstanding. 

While  there  are  and  always  will  be  both  lime  burners,  and  fer- 
tilizer manufacturers  who,  in  their  advice  to  farmers,  will  sacrifice 
the  interests  of  their  customer  and  their  own  future  business  deal- 
ings with  him,  to  the  profits  of  the  immediate  sale,  nevertheless  there 
is  already  a  decided  trend  towards  putting  the  business  on  a  better 
basis.  The  members  of  our  association  should  use  their  efforts  in 
furthering  this  movement  and  adhering  strictly  to  the  better  prin- 
ciple involved.  In  this  way  only,  can  we  hope  to  obtain  that 
confidence  in  our  goods  to  which  we  are  rightfully  entitled. 


But  if  we  are  to  correctly  advise  our  agricultural  trade,  then  we 
must  understand  our  subject  thoroughly.  It  is  broad  and  complex 
and  must  be  studied  diligently.  Still  it  is  founded  on  a  few  funda- 
mental facts,  which  are  exceedingly  simple.  It  is  these  facts  and 
the  position  of  lime  in  reference  to  them  with  which  we  are  here 
dealing. 

It  must  first  be  understood  that  there  are  eight  necessary 
ingredients  to  plant  life.  One  authority,  whom  we  will  accept^ 
states,  "Soils  contain  nitrogen,  phosphorus,  potassium,  calcium, 
magnesium,  sulphur,  iron  and  chlorine,  and  if  a  soil  is  deficient  in 
any  of  these  essential  elements  of  plant  food,  it  will  not  produce  a 
satisfactory  crop."  The  first  four  are  of  major  importance,  the 
last  four  are  minor.  Of  course,  it  is  well  known  that  other  things 
are  needed  such  as  soil-air,  moisture  and  humus  or  decaying 
organic  matter,  but  we  are  dealing  merely  with  the  mineral  chemis- 
try of  the  soil  and  plant  life.  Also  plants  need  carbon  for  their 
structure  and  this  is  obtained  both  from  the  atmosphere  and  from 
the  humus  of  the  soil,  which  in  decaying  evolves  the  gas,  carbon 
dioxide  or  carbonic  acid  gas. 

These  elements  do  not  appear  in  the  soil  or  plant  in  their 
elementary  form,  but  always  as  compounds.  It  is  to  be  noted  that 
of  these  substances  named  above,  some  are  acid-forming  and  others 
are  bases,  i.  e.  form  alkalis.  The  acid-forming  are  nitrogen,  phos- 
phorus, sulphur  and  chlorine,  becoming  respectively,  nitric,  phos- 
phoric, sulphuric  and  hydrochloric  acids.  Carbon  is  also  acid, 
forming  carbonic  acid.  The  bases  are  potassium,  calcium  and 
magnesium  forming  potassium,  hydroxide,  etc.  The  chemical  and 
popular  names  of  these  acids  and  alkalis  are  shown  on  Table  1, 
together  with  their  chemical  composition.  Iron  is  eitlier  acid  or 
alkali  according  to  conditions  surrounding  it. 

Acids  and  alkalis  combine  together  to  form  salts,  which  sub- 
stances in  general  show  neither  acid  nor  caustic  properties.  A  few 
familiar  examples  of  such  salts  are  calcium  phosphate,  commonly 
known  as  phosphate  of  lime,  magnesium  sulphate  or  Epsom  salts, 
and  potassium  nitrate  or  nitrate  of  potash. 

4 


Of  these  eight  materials  named  as  plant  foods,  the  custom  of 
the  trade  and  of  the  laboratories  has  seen  fit  to  nominate  only 
nitrogen,  phosphorus  and  potassium  as  fertilizers.  This,  however, 
should  cause  the  lime  manufacturer  but  little  concern,  for  lime 
covers  a  field  of  usefulness  far  broader  than  that  of  mere  plant  food. 
Crops  vary  considerably  in  their  requirements  of  the  different  sub- 
stances, as  shown  on  Table  2,  and  though  in  clover  it  is  observed 
that  the  lime  content  exceeds  that  of  some  of  the  three  so  called 
fertilizers,  still  lime  has  a  bigger  duty  to  perform  for  the  soil.  That 
duty  has  been  aptly  characterized  in  the  term  "A  Soil  Amendment." 

Before  proceeding  further  with  this  phase  of  our  subject,  we 
will  consider  certain  other  fundamental  facts.  All  of  these  mineral 
substances  must  enter  into  the  plant  as  salts.  Also  these  salts 
must  be  soluble,  for  in  plant  life  no  food  is  available,  nor  can  the 
plant  in  any  way  take  up  a  substance  except  it  be  in  solution.  This 
fact  has  been  demonstrated  in  the  laboratories. 

Now  since  some  of  the  nine  necessary  substances  are  acid  and 
some  are  alkaline,  it  would  be  ideal  if  fertilizing  salts  could  be  ob- 
tained in  which  both  the  acid  and  alkali  which  form  that  salt, 
would  be  of  use  to  the  plant.  But  this  in  general  is  an  impossibility 
owing  to  the  high  expense  of  such  balanced  salts,  as  for  example 
nitrate  of  potash,  which  furnished  both  the  major  ingredients  of 
potassium  and  nitrogen,  and  is  also  a  soluble  salt  therefore  quickly 
available.  Or,  in  the  case  of  sulphate  of  potash,  the  plant  is  so 
much  more  in  need  of  the  potash  than  of  the  sulphur,  that  it  takes 
the  former,  leaving  the  latter  to  sour  the  soil.  Nitorgen  has  a 
peculiarity  which  should  here  be  noted.  It  is  commonly  called  an 
acid  substance,  forming  nitric  acid  and  thence  the  salts  known  as 
nitrates.  But  nitrogen  also  combines  with  hydrogen  to  form  an 
entirely  different  substance,  ammonia,  which  strange  to  say,  is 
strongly  alkaline,  forming  when  properly  combined  with  acids, 
salts  of  ammonia,  as  for  example,  sulphate  of  ammonia.  It  will 
even  combine  with  nitric  acid  to  form  nitrate  of  ammonia,  an  ideal 
fertilizing  salt  for  nitrogen  only,  but  this  is  an  artificial  salt,  never 
occurring  naturally   and  would   be   very  expensive. 

5 


In  fertilizers,  nitrogen  is  most  easily  gotten  as  a  salt  of  ammon- 
ia, so  that  the  plant,  in  utilizing  the  ammonia,  i.  e.  nitrogen,  sets 
free  the  acid  in  the  soil.  With  potassium,  an  alkaline  material, 
the  same  action  takes  place.  If  a  phosphate  salt  is  used,  the  re- 
verse takes  place,  that  is  the  plant  utilizes  the  phosphoric  acid  and 
sets  the  alkali  free.  But  phosphate  salts  are  quite  insoluble,  so  that 
in  general  they  are  treated  with  acid  to  form  acid  phosphates  or 
superphosphates,  which  acid  salts  are  soluble,  but  the  sweetening- 
effect  on  the  soil  of  setting  free  an  alkali  is  therebv  greatlv  reduced. 
The  insoluble  phosphate  salts  are  however  used  with  considerable 
success  and  this  will  be  taken  up  later. 

Hence  it  is  seen  that  the  effect  of  using  the  three  fertilizers  is  to 
sour  the  soil  with  acid  and  in  order  to  counteract  this  tendency, 
some  alkali  must  be  supplied.  Lime  is  at  once  the  cheap  and  the 
efficacious  material  to  accomplish  this  end,  because  it  readily 
forms  the  salts  with  the  acids,  thus  neutralizing  the  soil.  There  are 
practically  only  two  acids  met  with,  sulphuric  and  hydrochloric  or 
muriatic  and  the  two  salts,  sulphate  and  muriate  of  lime  will  remain 
inert  in  the  soil,  pending  the  desire  of  the  plant  to  utilize  any  part 
of  them.     This  is  one  of  the  uses  of  lime  as  "A  Soil  Amendment." 

The  Form  Which  His  Fertilizers  are  to  be  in  for  their 

Application. 

It  is  evident  therefore  that  the  farmer  should  exercise  care  in 
selecting  the  form  in  which  he  applies  his  fertilizers,  so  as  to  get  a 
maximum  of  valuable  material  and  a  minimum  of  inert  valueless 
substances  left  in  the  soil.  And  he,  as  well  as  the  fertilizer  manu- 
facturer, must  realize  that  fertilizers  in  general  are  inherently 
sourino-  to  the  soil,  and  that  lime  is  the  onlv  satisfactory  means  of 
restoring  the  soil  to  a  condition  where  it  can  once  more  profit  by  the 
use  of  fertilizers.  Conversely,  the  lime  manufacturer  must  realize 
that  nitrogen,  phosphorus  and  potassium  are  major  needs  of  the 
plant  and  must  be  supplied.  Whenever  phenominal  results  have 
been  obtained  from  the  use  of  lime,  it  is  invariably  due  to  the  fact 
that  the  fertilizers  were  already  present  in  the  soil  in  ample  quanti- 

0 


ties  and  there  was  only  needed  the  presence  of  Hme  either  in  its 
lesser  capacity  as  a  plant  food,  or  in  some  form  of  its  greater  func- 
tion as  a  soil  amendment  to  accomplish  the  wonderful  results 
observed.  Every  agricultural  lime  marmfacturer  should  therefore 
be  prepared  to  give  his  customer  full  information  and  advice  as  to 
where  and  in  what  form  the  so  called  fertilizers  can  most  economi- 
cally be  bought. 

Many  farmers  believe  that  they  are  subserving  all  the  needs  of 
their  soil  by  returning  the  manure  to  it  from  the  stables  and  by  the 
occasional  growth  of  some  fertilizing  crop.  That  this  belief  is 
without  foundation  and  wholly  fallacious  is  easily  explained. 

Matter  in  its  elementary  form  can  neither  be  destroyed  nor 
created.  If  the  analysis  of  a  crop  shows  that  it  contains  so  much 
potassium,  so  much  phosphorous,  etc.,  then  those  materials  come 
from  the  soil.  The  soil  also  loses  through  leaching.  Now  if  that 
crop  goes  to  feed  a  dairy  herd,  then  these  valuable  mineral  ingre- 
dients are  distributed  to  milk,  to  flesh  of  the  growing  animal  and 
to  the  manure,  both  liquid  and  solid.  Obviously,  neither  the 
milk  nor  the  flesh  of  the  animal  finds  its  way  back  to  the  soil.  In 
addition,  authorities  state  that  a  large  portion  of  the  fertilizer  value 
of  the  manure  is  lost  through  improper  protection  and  handling. 
Accordingly,  but  a  small  percentage  of  the  mineral  matter  taken 
from  the  soil  ever  gets  back  to  it.  The  necessity  of  replacing  it  is 
self  evident. 

It  is  well  then  to  consider  how  the  farmer  can  most  economi- 
cally obtain  the  difl^erent  plant  foods,  all  of  which  are  necessary 
for  successful  crops. 

Nitrogen:  This  is  the  most  expensive  of  all  fertilizers  to  buy 
and  the  cheapest  for  the  farmer  to  make.  If  bought  in  the  form  of  a 
nitrate  or  of  a  salt  of  ammonia,  the  cost  will  usually  be  greater  than 
15  cents  per  pound,  of  actual  nitrogen.  Table  III  shows  that  the 
purchase  of  nitrogen  at  such  a  price  for  the  use  of  tlie  staple  crops  is 
practically  prohibitive.  On  the  other  hand  nitrogen  is  evolved  in 
all  decaying  animal  or  vegetable  matter.  Therefore,  any  organic 
waste  is  the  proper  fertilizer  for  obtaining  nitrogen  and  fresh  manure 

7 


stands  pi-e-eminent.  But  by  far  the  most  prolific  source  of  nitro- 
gen is  the  atmosphere  itself  which  is  composed  of  80%  of  this 
valuable  element.  Clover,  alfalfa  and  other  legumes  have  the 
power,  through  tubercle  germs  growing  on  their  roots,  of  fixing  the 
free  nitrogen  of  the  air  into  compounds  available  for  plant  food. 
Several  of  the  legumes  can  be  grown  as  catch  crops  between  regular 
rotation  crops,  the}^  can  be  harvested  with  profit,  and  the  roots 
turned  imder,  not  only  greatly  enriching  the  soil,  in  nitrogen,  but 
also  increasing  the  quantity  of  humus  and  improving  its  physical 
condition.  This  method  is  by  far  the  best  and  cheapest  of  return- 
ing nitrogen  to  the  soil.  The  absolute  necessity  of  lime  for  the 
growth  of  clovers  and  other  legumes  is  now  an  accepted  fact  by 
all  authorities.  Many  farmers  grow  buckwheat,  barley  or  rye  as 
a  green  manure  for  turning  under,  but  these  crops  positively  will 
not  return  any  nitrogen  or  other  fertilizer  to  the  soil  except  that 
which  they  took  from  it. 

Phosphorus  :  This  occurs  naturally  as  phosphate  rock  which 
is  chemically  phosphate  of  lime.  When  finely  ground  it  is  known 
commercially  as  "floats."  In  the  process  of  manufacture  of 
"commercial  fertilizer,"  it  is  treated  with  sulphuric  acid,  and  is 
changed  to  an  acid  phosphate,  which  is  soluble.  This  reaction 
reduces  the  percentage  of  phosphorous  to  one-half  that  contained  in 
the  original  raw  rock. 

By  far  the  cheapest  and  most  far-sighted  method  of  applying 
phosphate  is  as  floats.  Since  it  is  insoluble  it  will  not  be  leached 
out.  It  can  therefore  be  applied  in  quantities  sufficient  for  several 
years  cropping.  It  becomes  slowly  available  through  the  natural 
tendency  of  all  soils  to  become  acid.  It  is  attacked  and  rendered 
available  by  the  evolution  of  carbon  dioxide  either  through  the  de- 
cay of  humus  or  through  the  decomposition  of  ground  limestone. 
It  is  very  satisfactorily  used  as  an  absorbent  of  the  liquid  portion  of 
stable  manure.  It  may  be  top  dressed  on  clover  sod  and  turned 
under.  When  thus  turned  under  with  manure  or  clover,  the  floats 
are  acted  on  by  the  acids  of  the  decaying  organic  matter.  If  imme- 
diate results  are  desired,  it  is  well  to  put  on  a  small  portion  of  acid 


phosphate,  sufficient  for  the  first  year's  crop  along  with  the  floats 
for  the  more  permanent  results. 

The  manufacturers  of  floats  claim  for  it  a  complete  fertilizer 
in  that  it  contains  both  phosphorous  and  lime,  stating  that  all  soils 
contain  huge  stores  of  potash  and  calling  on  the  air  for  the  nitrogen. 
The  weak  points  in  this  claim  are  first  that  in  general  only  the  heavy 
clay  soils  are  rich  in  potash  and  this  is  in  a  form  rendered  available 
only  through  the  use  of  caustic  lime,  and  second,  nitrogen  is  secur- 
able  from  the  air  only  through  the  clovers,  which  crop  usually  fails 
unless  well  supplied  with  lime  in  addition  to  that  in  the  phosphate 
rock.  Nevertheless  finely  ground  phosphate  rock  is  an  excellent 
and  cheap  carrier  of  phosphorous  and  as  such  its  use  should  be 
encouraged  wherever  permanent  enrichment  of  the  soil  is  desired. 

Other  sources  of  phosphorous  are  certain  slags  and  some  organ- 
ic matters  such  as  bone.  These  forms  like  floats  are  all  slowly 
available  and  as  such  should  be  finely  ground. 

Potassium:  The  stores  of  insoluble  potash  that  many  soils 
contain  may  be  rendered  available  by  the  use  of  lime.  But  such 
drawing  upon  the  capital  cannot  be  continued  indefinitely,  so  that 
the  application  of  a  certain  amount  of  potash  fertilizer  is  to  be 
recommended.  Various  potash  salts  can  be  purchased  in  the  crude 
form.  Much  is  imported  from  Germany  as  chorides  and  sulphates, 
as  well  as  kainit,  a  cheaper,  cruder  natural  product.  Wood  ashes, 
cotton  seed,  hull  ashes,  tobacco  stems  and  barn  yard  manure  are 
all    carriers  of   potash. 

Calcium  and  Magnesium:  These  not  only  form  necessary 
plant  food,  but,  as  stated  previously,  fill  the  larger  field  of  soil 
amendment.  While  this  has  now  come  to  be  an  accepted  fact,  it  is 
such  a  broad  and  intricate  study  that  it  can  only  be  touched  on 
lightly  here.  In  regard  to  the  oft-heard  controversy  of  calcium 
vs.  magnesium,  I  will  quote  from  Ohio  Agricultural  Experiment 
Station  Bulletin  No.  159.  "Magnesia  is  as  necessary  to  plant 
growth  as  lime;  it  is  probably  equally  effective  with  lime  in  the  neu- 
tralization of  soil  acidity  and  in  the  amelioration  of  the  physical 
condition  of  the  soil;  so  that,  for  ordinary  agricultural  purposes,  the 

9 


proportion  of  magnesia  in  a  limestone  is  a  matter  of  no  consequence. 
It  is  true  that,  under  certain  conditions,  an  excess  of  magnesia  may 
be  hurtful  to  vegetation,  and  it  could  not  be  advisable  to  use  a  pure 
salt  of  magnesia  as  a  fertilizer  on  this  account;  but  it  has  been  shown 
that  so  long  as  lime  is  in  excess  of  magnesia,  no  injurious  results 
follow  its  use." 

There  is  no  occasion  for  unseemly  quarreling  between  the  high 
calcium  and  the  magnesian  lime  manufacturers.  They  have  a 
common  cause.  In  general,  the  farmer  should  purchase  the  cheap- 
est lime,  when  calculated  for  available  oxides,  delivered  and  spread, 
only  I  would  make  this  recommendation : — ^That  where  a  farmer  has 
been  continually  using  high  calcium  lime,  he  should  occasionally 
give  his  fields  a  treatment  of  magnesian  lime  and  vice  versa. 

Calcium  is  also  obtained  as  gypsum  or  land  plaster,  but  since 
this  is  a  sulphate,  it  follows  that  the  plant  in  utilizing  the  calcium, 
sets  free  sulphuric  acid,  thereby  souring  the  soil.  This  method  of 
applying  calcium  is  therefore  to  be  avoided. 

Ground  limestone  is  calcium  carbonate,  a  neutral  salt.  It  is 
particularly  adaptable  as  a  filler  for  all  fertilizers  for  home  mixing. 
It  will  not  break  up  compounds  of  ammonia,  setting  free  the  latter 
to  be  lost.  Accordingly  it  is  a  good  absorbent  of  stable  manure. 
While  of  a  neutral  nature  it  is  readily  broken  up  itself  by  the  strong- 
er acids,  such  as  sulphuric  and  hydrochloric.  Hence  it  is  an  auto- 
matic rectifier  of  soil  acidity,  always  remaining  inert,  and  insoluble 
in  the  meantime.  When  thus  broken  up  by  a  stronger  acid,  car- 
bonic acid  is  set  free,  but  this  acid  is  so  exceedingly  weak  that  it 
further  breaks  up  into  water  and  carbonic  acid  gas  or  carbon 
dioxide  and  this  gas  is  exactly  the  same  as  that  which  the  plant  takes 
from  the  atmosphere,  and  from  the  decaying  humus  of  the  soil, 
for  the  building  of  its  own  carbonic  structure.  It  is  easy  to  conceive 
that  the  setting  free  of  carbon  dioxide  in  the  soil  is  helpful  rather 
than  detrimental  to  the  plant. 

The  same  rule  as  to  fineness  of  grinding  of  phosphates  applies 
to  ground  limestone.       In  fact,   I    am   fully   of  the   opinion   that 

10 


material  which  will  not  pass  through  a  50  mesh  screen  might  as 
well  not  be  put  on  the  soil. 

Many  authorities  hold  that  all  the  needs  of  the  soil  are  sub- 
served by  the  use  of  ground  stone,  always,  of  course,  based  upon  the 
amount  of  the  oxide  content.  The  argument  for  this  is,  that  if 
lime  is  applied  either  as  oxide  or  hydrate,  it  very  quickly  takes  up 
carbon  dioxide  from  the  air  and  returns  to  the  carbonate  form 
in  an  exceedingly  finely  divided  state.  But  one  of  the  well  known 
actions  of  lime  as  a  soil  amendment,  is  the  rendering  available  of 
inert  compounds  of  potash,  with  which  many  soils  abound.  Now 
lime  cannot  perform  this  function  unless  in  an  active  state.  It  is 
evident  that  if  either  ground  lime  or  hydrate  is  harrowed  into  the 
soil,  it  will  be  more  or  less  protected  from  the  carbon  dioxide  of  the 
air.  and  will  better  perform  its  duty  of  freeing  the  potash.  Also, 
being  thus  protected,  it  tends  to  keep  the  entire  soil  alkaline,  a 
condition  usually  considered  favorable  to  plant  life  by  most  investi- 
gators. Therefore,  it  is  my  opinion  that  whereas  ground  lime- 
stone is  the  proper  material  for  a  filler  of  fertilizers,  nevertheless 
when  liming  is  done,  as  it  should  be  at  least,  once  in  the  cycle  of 
crop  rotation,  it  should  be  done  with  ground  or  hydrate  lime. 
Ground  limestone  is  of  value  however  in  rendering  ground  phos- 
phate rock  available.  It  performs  this  function  because  of  the 
fact  that  as  a  carbonate  it  is  readily  decomposed  by  practicallv  all 
soil  acids.  The  carbon  dioxide  evolved  will  in  turn  acidulate  the 
phosphate  turning  it  to    a  superphosphate  which  is  available. 

The  question  of  whether  it  is  better  to  use  ground  quick  lime 
or  hydrate,  each  farmer  must  decide  for  himself.  Delivered  cost 
of  actual  oxide,  ease  of  handling,  machinery  for  applying,  all  enter 
into  the  consideration.  I  would  personally  prefer  the  use  of  ground 
lime  on  account  of  greater  economy  of  purchasing  and  applying, 
except  only  in  such  crops  which  might  be  injured  by  the  more  vio- 
lent action  of  the  quick  lime;  in  which  case  the  hydrate  will  be  found 
to  be  milder.  Wherever  it  is  desired  to  have  an  actively  alkaline 
lime  which  still  must  be  mild  in  its  action,  it  is  necessary  to  use  the 
hydrate  form. 

11 


Stjlphur  and  Chlorine:  Some  authorities  claim  that  these 
acid  substances  are  not  necessary  to  plant  growth,  but  that  plants 
will  take  them  up  in  limited  quantities  when  present.  Be  that  as  it 
may,  since  potash  is  most  easily  obtained  in  the  form  of  sulphates 
and  chlorides,  the  general  tendency  is  for  too  much  of  these  sub- 
stances to  get  into  the  soil  rather  than  that  a  deficiency  should  exist. 
Therefore,  the  farmer  should  take  care  not  to  overload  his  soil  with 
these  materials,  but  still  see  to  it  that  his  potash  is  sometimes  gotten 
as  sulphates  and  chlorides.  Whether  it  is  better  to  purchase  potash 
as  a  chloride  or  sulphate  can  usually  best  be  decided  by  an  inquiry 
into  the  requirements  of  the  crop  immediately  following.  Potatoes, 
tobacco  and  sugar  l)eets  are  benefitted  by  the  sulphate  form,  while 
other  plants  seem  to  prefer  the  chloride. 

Iron  :  It  usually  abounds  to  an  extent  in  all  soils  sufficient  for 
the  limited  requirements.  It  is  also  being  constantly  added  through 
the  other  fertihzing  materials,  which  invariably  contain  a  small  per- 
centage of  this  metal  as  an  oxide.  It  has  never  been  considered 
necessary  that  this  element  be  specifically  added  to  the  soil. 

In  commercial  fertilizers,  the  valuable  ingredients  form  but  a 
very  small  percentage  of  the  total,  the  most  part  being  worthless 
filler.  iVn  analysis  of  many  fertilizers  on  the  market  shows  that  the 
manufacturer  takes  from  $10 .  00  to  $'20 .  00  per  ton  to  cover  his  cost 
of  mixing,  bagging  and  profit.  In  other  words,  the  farmer  pays 
that  much  more  for  his  fertilizing  materials  than  if  he  bought  them 
in  the  concentrated  form.  Hence  it  has  become  good  practice  to 
purchase  concentrated  fertilizers,  mix  them  in  the  barn,  and  add  a 
desirable  filler  which  is  necessary  to  get  distribution  of  the  concen- 
trates uniformly  over  the  ground.  And  there  is  no  more  valuable 
nor  more  efficacious  filler  than  ground  limestone.  There  are  a 
great  host  of  bi-products  and  natural  products  which  claim  to  have 
special  fertilizing  powers.  Ground  bone,  tankage,  fish  refuse, 
dried  blood,  lava  dust,  various  ashes,  slags  and  so  on  without 
number.  When  the  farmer  is  importuned  to  buy  such  materials, 
he  should  simply  request  a  guaranteed  analysis,  then  calculate  for 
the  nitrogen  contained  at    15  cents    per  pound,  phosphorous   at 

12 


5  cents  and  potassium  at  5  cents  and  then  determine  whether  he 
desires  the  fertilizer  elements  contained  and  what  it  is  worth  to 
him  delivered.  It  is  always  well  to  have  such  analysis  and  calcu- 
lations checked  by  the  experimental  station. 

liCt  this  paper  then,  be  the  humble  herald  of  a  new  era  in 
supplying  the  needs  of  the  farmer.  Having  studied  his  needs  intelli- 
gently, let  us  not  be  afraid  to  recommend  to  him  the  use  of  potash 
and  phosphate  but  rather  let  us  carry  a  list  of  names  of  suppliers, 
where  these  materials  in  concentrated  form  can  be  purchased 
economically:  then  tell  him  the  ground  stone  necessary  as  a  tiller 
and  the  aoricultural  lime  that  he  will  need  the  vear  foUowino;.  It 
is  not  proposed  at  this  time  to  say  how,  when,  or  in  what  propor- 
tions the  various  mineral  elements  should  be  added  to  the  soil  for 
various  crops.  This  information  can  be  readily  gotten  from  the 
experimental  stations.  A  table  similar  to  table  II  showing  analysis 
of  the  ash  of  different  plants  is  the  best  guide. 

Let  us  summarize  our  new  policy  of  education  and  of  selling 
lime  to  the  farmer  as  follows: — 

1st.  Nitrogen,  potassium,  phosphorous  and  lime  are  all  im- 
portant necessities  of  the  soil  and  chlorine,  sulphur  and  iron  are 
minor  ones. 

2nd.  Nitrogen  being  a  very  expensive  fertilizer  to  purchase, 
should  be  returned  to  the  soil  by  stable  manure,  and  by  the  growing 
of  legumes  for  which  lime  is  needed. 

3rd.  Potash  and  phosphate  should  be  purchased  in  concen- 
trated forms  and  mixed  in  proper  proportions  to  suit  the  crop  to  be 
gro\^'n  and  the  deficiencies  of  the  soil  to  be  treated.  Ground  lime 
stone  will  be  found  excellent  as  a  filler. 

4th.  Use  lime  in  either  quick,  ground  or  hydrate  form  at  least 
once  in  the  cycle  of  crop  rotation,  at  a  time  shortly  prior  to  the  seed- 
ing of  the  crop  of  clover  or  other  legume.  Lime  in  this  form,  well 
harrowed  in,  will  help  materially  in  rendering  valuable  the  inert 
potashes  of  the  soil  and  in  keeping  the  soil  in  the  slightly  alkaline 
condition,  desirable  for  most  plant  growth. 

13 


5th.  Stable  manure  being  the  greatest  of  all  fertilizers  should 
be  carefully  conserved,  and  its  liquid  portion  absorbed  by  ground 
phosphate  rock  or  ground     limestone. 

6th.  Run  in  a  catch  crop  of  clover  between  the  regular  rota- 
tion crops  whenever  possible.  The  harvest  will  pay  for  the 
trouble  and  the  roots  will  immenselv  enrich  the  soil  in  nitrogen  and 
humus. 

7th.  Sulphates  and  chlorides  should  be  used  sparingly,  and 
then  only  as  compounds  for  the  carrying  of  potash.  The  ground 
limestone  used  as  fertilizer  filler  and  stable  manure  absorbent  will 
usually  be  sufficient  to  correct  the  scouring  tendency  of  these  acid 
materials. 

8th.  Fertilizers  in  the  mineral  form  do  not  improve  the  physi- 
cal condition  of  the  soil,  nor  increase  its  content  of  humus.  Accord- 
ingly whenever  organic  fertilizers  are  cheaply  available,  give  them 
the  preference.  The  souring  tendency  of  rotting  organic  matter 
when  detected,  can  be  corrected  by  liming. 

9th.  Lime,  whether  considered  to  be  a  fertilizer  or  not,  forms 
a  necessary  part  of  all  plant  life.  But  far  greater  is  its  field  as  a  soil 
amendment,  to  lighten  clay  soils,  to  compact  sandy  soils,  to  make  soil 
more  healthful,  to  foster  desirable  germ  life,  and  to  render  avail- 
able for  the  plant,  other  foods  and  fertilizers  contained  by  the  soil. 

10th.  The  farmer  loses  a  large  portion  of  the  value  of  lime 
if  he  fails  to  use  it  as  a  means  of  growing  clover  or  other  legume. 
This  is  the  natural  and  only  cheap  method  of  returning  the  expen- 
sive and  necessary  nitrogen  to  the  soil.  For  financial  success  in 
farming,  it  must  be  done. 

11th.  Farming  is  a  manufacturing  enterprise  and  the  soil  is  a 
factory.  The  amount  of  finished  material  in  entirely  a  function  of 
the  raw  material  supplied  and  the  labor  used.  It  the  farmer  is  to 
follow  modern  factory  practice  of  obtaining  the  greatest  possible 
out-put  from  his  property,  then  he  must  feed  in  the  raw  material 
diligently  and  intelligently  as  well  as  till  the  soil,  and  in  this  policy 
he  will  find  lime  his  strong  right  bower  in  intensifying  production 
and  in  getting  the  greatest  and  completest  value  from  his  fertilizers. 

14 


Note    on  Adding  Lime  to  the  Soil. 

1.  In  general,  modern  agriculture  limes  are  much  purer  than 
those  of  a  generation  ago.  Accordingly  their  action  is  much  more 
intense.  Smaller  quantities  must  be  used  and  carelessnesss  on  the 
part  of  the  user  may  harm  the  soil. 

2.  Ground  lime  and  hydrated  lime  must  be  used  in  very  much 
smaller  quantities  than  other  forms  on  account  of  the  fact  that  a 
more  intimate  mixture  between  the  soil  humus  and  active  lime  is 
obtained  with  them,  than  with  the  older  form  of  run  of  kiln  and  air 
slacked  lime. 

3.  The  practice  of  drilling  hydrated  lime  with  clover  seed  has 
been  found  successful  but  must  be  done  with  great  care  and  only 
under  the  advice  of  an  experimental  station. 

4.  Ground  limestone  is  "fool-proof."  It  can  be  applied  to  a 
soil  in  any  desired  quantity  within  reason,  so  as  to  suffice  for 
many  years,  without  in  any  way  endangering  the  soil.  It  leaches 
out  but  very  slowly.  The  limestone  should  be  ground  so  that  it  will 
all  pass  a  12  mesh  screen  and  at  least  50%  should  pass  100  mesh. 

5.  Quick  lime,  hydrated  lime  and  ground  limestone,  all  have 
the  same  ultimate  effects.  Their  respective  total  values  are  based 
upon  the  available  oxide  of  lime  and  magnesia  present.  In  good 
grades  of  materials  these  available  oxides  should  run  in  excess  of 
the  following, — Ground  lime  86%,  hydrate  77%,  ground  limestone 
46%. 

6.  Lime  or  ground  limestone  can  to  advantage,  be  spread 
upon  the  field  any  time  during  the  winter  on  frozen  ground.  This 
is  particularly  desirable  on  level  ground.  On  rolling  or  hilly 
country  there  is  danger  of  the  material  being  lost  thru  surface 
washing  unless  the  ground  is  protected  by  a  cover  crop.  Ground 
limestone  is  less  susceptible  to  surface  washing  and  hydrate  lime 
most  susceptible  until  it  gets  thoroly  wet  and  incorporates  with 
the  soil. 

7.  Many  chemical  tests  are  proposed  for  the  determination  o^ 
whether  the  soil  does  or  does  not  need  lime.     These  tests  require 

15 


special  materials  and  a  certain  technical  knowledge,  and  it  is  to  be 
preferred,  therefore,  that  a  farmer  should  determine  the  require- 
ments of  the  soil  by  its  history  and  appearance.  If  the  soil  has  been 
richly  supplied  with  manure  and  fertilizer  and  cropped  regularly 
for  several  years,  then  it  is  certainly  in  need  of  lime,  even  tho  it 
should  be  overlaying  limestone.  If  the  soil  refuses  to  give  a  good 
crop  of  clover,  and  is  inclined  to  grow  weeds,  such  as  sorrel,  etc., 
"then  lime  is  quickly  needed. 


References  in  Connection  With 
'The  Position  of  Lime  in  the  Chemistry  of  the  Soil." 

Ohio  Agricultural  Experimental  Station,  Lyster.   Ohio. 
Bulletin  No.   159. 

"Manual  of  Practical  Farming,"  Joseph  McLennan  (McMul- 

lin    Co.) 

* 'Farmers    Cyclopedia    of    Agriculture,"    Wilcox     &    Smith 

(Orange    Jud    Co.,    New   York). 

""Principles  of  Profitable  Farming"  and  "Plant  Foods"  issued 
by  the  German  Kali  Works,  Baltimore,  ^Id. 

"Compendium  of  Results  of  the  Agricultural  Stations  of 
Illinois,  Ohio,  Maryland,  Pennsylvania  in  the  use  of 
Ground  Rock  Phosphate,"  issued  by  the  Farmers 
Ground  Rock  Phosphate  Co.,  of  Mt.  Pleasant,  Tenn. 

Rhode     Island     Agricultural     Experimental     Station, 
.      Bulletin  No.   46. 
16 


"o 

Xi 

s 

;>^ 

'V, 

M 

'o 

as 

'S 

'B 

v 

U 

o  _ 


^       K  W  ffi  K  W 


Oh  ^ 


c 

-M        3 

o  .5  ^  j±; 
^  ^  c/2  C. 


0;  p^ 
O 
Ph 


H  ^ 

^s 

w  5 

^< 

O 

a  Ts 

03   'G 

;^  -Ji 

^  -c 


;z;  ffi  rj2  p^  Ph 


o  o 


OJ 

s 

It 

^ 

.ii  K 

-^    /,i 

c^ 

M       OJ 

3 

i.s 

o 

U  h3 

Ph 

in. 
o 
Ph 


a; 

s 

^ 

w 

^ 

s 

t^ 

O 

o 

CO 

Ph 

<u 

Is 

l+H 

-4-1 

CA2 

o 

^ 

^ 

V 

O 

c3 

O 

w 

^ 

£ 

i^ 

C^  CN 


-^o 


r-    h-H    _5^      N    C3     _. 
^    HH    -;r    Hrl      ^H    O 


a  -a 


Iz;  u  ctj 


pi- 


o 

X5 


C/2 


fcJD 


■p. 

P 

-3 


s  5  's  w 


O    GO 


bX) 


^piw. 


p^ 


:^ 


3 

p 

a 

_o 

3 

.5 

'  S          y 

o 

4.J 

'co 
c« 

a 

.5 

a; 

s?rpH  -^  O  .?^  O 

-^    o 

CO 

o 

Ph 

o3 
O 

Ph 

o 

bJO 
05 

P 
1-3 

< 

17 


O 


o 


o 

X 


72 

'o 

<1 

c 

cc 

O 

PT 

r-* 

ffi 

CO 


GO 


O 

P^ 


CO 


05 


GO 


^ 


i:S 

c 

W 

^^ 

g 

O 

;z; 

GO 
00 

05 

to 

1— 1 

ce 

-M 

S 

g 

1-1 

<u 

PQ 

o 

<I 

H 

o 
o 

V 

-M 

^ 

1* 

O 
O 

o 

o 

O 
O 

-M 

^'' 

o_ 

®t 

o_ 

^H 

^ 

C^ 

«D 

GO 

go" 

d 

V 

^ 

CU 

CT^ 

!« 
3 

a 

PC 

o 

;-< 

!-( 

O 

^ 

^^     ^ 

m 

2 

O 

O 

>-o 

3 

t~ 

CO 

GO 

o 
o 
o. 


o 
o 
o 


S 

X 

o 

a, 


1^ 


a, 

a 


p 


CJ 


05 

O 


18 


U 


o 
o 
Pi 


w 


o 

pa 


p:3  P^ 

U  o 

1— 1 

^  W 

I— I 

Iz;  p^ 

t— 1  c/:- 

H 

C/2  O 

hJ 

^-  ffi 

PQ 

;^  p- 

<: 

^       CJ 

H 

Um4         ^ 

^  i^~^ 

h-!  vi- 

Wk 

o  ^ 

^^ 

HH  r^ 

^s  o 

3Ph 

1— 1 

H  pq 

P^    M 

fv,-   M 

W 

r^    Ph 

o 


72. 
"C 


^       o 


3 
pa 

:; 

;; 

O 

-M 

- 

- 

- 

Oh 

- 

o 

GO 

o 

GO 
GO 

GO 

i>  >o 


(Xj   o 


CO  00 


-c  j:; 


Ci 


GO       1^ 


O     O       GO    Tf* 


©>    O       Ci    X       i>    to 


Oh  I 


o 


to 


>0    CO 


o 
o  o 


o 


Oh^ 


O 


0; 


3 

bJD 


O 
-X- 


p     fl 

33    c 


0) 


CO     cu 
33  -^ 

'^    o 

b€-d 

S       CO 

T'     tn 

bjo  o; 

-M 


<M-H 

^    c 


'1^  ^ 


.0)     bJD' 


c    c 


c3   'TJ 
o;    c 


w 


--5   5 

bD   N   ^ 


CO 

O 


O-' 


41j         en 


0^ 
O 

Ch:t2 


bi)  o 
O      OJ 

CO 


;:2     ^     c3 


T;  ^    3 


0;    -^ 


<u    s 


c5 

c 


aj    ^ 


2; 


O     _     en 
r-      Ch      (/; 

CO    *"" 


H   cT 


C    1/    aj 
IK    a*  •« 


o 


o 


19 


o 


h  ^    c    ^ 


o  z^ 

rH  C 

2    -i  Xi 

CU        iH  C 


^UJttt*»ATO 


mMm 


i! 


!  i 


mm^ 


^itihi 


mm 


m 


mmm 


!?«' 


;=    :.■>'{> 


I'l 


If!.'  ?i 


lil 


(ti. 


! 


j!!;|{l!!!:i! 


1 


iitiip^'i! 


mm 


'<  i  l;i' 


!ll! 


It]    J 


/     i,  '•(  •» 


•M 


filiiliiilj 


i 


:!!j! 


.'iiiii; 


■fliilil 


'M!VH)\V)U 


!  i'tiiilji;/'     1 


i     ! 


'^!'('i||'!li 


M  :*f't>';;!ii 


'isJiilillil 


i;  t  i 


f 

:'^^i! 


111! 


ri  J    U  » 


ii. 


miOiHiffffiH 


